How to access the contents of an error response in Volley?

Question

Using any of these examples: http://developer.android.com/training/volley/request.html

I understand how to process the response of a succesful request, and how to detect and react to an error.

However, an error may be (among other situations) a 40x or 50x response from the server, in which case the response can still contain data (headers and body).

But the error listener is only passed a VolleyError object (which is a subclass of Exception if I'm not mistaken) and not a Response object.

How do I access the content of an error response?

Answer 1

The VolleyError object has a networkResponse reference, which itself has a 'data' member, which is a byte array of the response body. If you want to view the data in the case of an error code in response, you can use something like this:

@Override public void onErrorResponse(VolleyError error) {     String body;     //get status code here     String statusCode = String.valueOf(error.networkResponse.statusCode);     //get response body and parse with appropriate encoding     if(error.networkResponse.data!=null) {         try {             body = new String(error.networkResponse.data,"UTF-8");         } catch (UnsupportedEncodingException e) {             e.printStackTrace();         }     }     //do stuff with the body... } 

Answer 2

In StringRequest for example:

@Override protected Response<String> parseNetworkResponse(NetworkResponse response) {     Map<String, String> responseHeaders = response.headers;     if (response.statusCode == 401) {         // Here we are, we got a 401 response and we want to do something with some header field; in this example we return the "Content-Length" field of the header as a successfully response to the Response.Listener<String>         Response<String> result = Response.success(responseHeaders.get("Content-Length"), HttpHeaderParser.parseCacheHeaders(response));         return result;     } // else any other code that carries a message     return super.parseNetworkResponse(response); }